Called the AspireAssist device, it works by sucking the food right out of the stomach so that only about a third of the calories are absorbed by the body.

Patients wait 20 minutes after eating, then empty 30 percent of their stomach contents into the toilet through a tube — a small, handheld device connects to a skin-port discretely embedded on the outside of the abdomen.

Calories not digested are calories not absorbed, which, say the inventors, leads to weight loss.

In a one-year trial of 24 obese patients, patients on average lost 49 percent of excess weight, the equivalent of about 45 pounds.

Mikael Cederhag, 55, of Sweden was one of them. When he had the AspireAssist device implanted last year he tipped the scales at 264 pounds. Now he’s at 200 pounds and still losing.

“This is it for me. I’ve been jumping up and down in weight for 30 years,” Cederhag said. “Finally, this is a solution that allows me to get my weight down and stay that way.”

Katherine D. Crothall, president and CEO of Aspire Bariatrics, the maker of the AspireAssist, said she understood why people might find the idea of the pump “gross” but insisted it offered a viable way for morbidly obese people to drop pounds.

“Some people manage to lose weight on a diet, but the kinds of changes you need to make to keep it off are probably not sustainable for many,” she said. “There’s a lot to be said for people being in the driver’s seat with their own body, with their own health. This allows a patient to do that while under the care of a physician.”

Available in select regions of Europe, including Sweden, since 2011, the AspireAssist is still undergoing trials in the United States, and the Food and Drug Administration has yet to approve it for use here.

“That’s not the kind of life I wanted,” he said, noting the pump could be removed in 15 minutes by a doctor.

Dr. Jaime Ponce, a bariatric surgeon and president of the American Society for Metabolic and Bariatric Surgery, countered that surgery could aid weight loss beyond simply shrinking the stomach.

“Surgery changes hunger sensations and portion size capability. There are also some hormonal changes that take place to allow patients to make better food choices,” he said. “If you eat a lot of sweets and greasy food after having surgery, you don’t feel good.”

Ponce said the pump’s trial demonstrated a promising amount of weight loss, but the study was too small and too short to draw any real conclusions from it. Ponce’s biggest worry was that the AspireAssist device didn’t seem to address hunger.

“If you pump the stomach, the patient is hungry again,” he pointed out. “I don’t see how this gets around that.”

But Cederhag said he never felt hungry. “Because you leave the food in the stomach for 20 minutes, your brain registers that you are filled up. That sensation stays even after you have flushed out the 30 percent of food.”

Behavior Change Is Key

Keith Ayoob, an associate clinical professor of nutrition at Albert Einstein College of Medicine in New York City said he was horrified by the stomach-pumping machine — but he’s not surprised it was invented.

“People often wish they could just eat and make the calories go away,” he said. “It was only a matter of time before someone came up with this.

“This is an enabling device, not a helping device,” Ayoob continued. “It doesn’t do anything to make someone change their relationship with food. Once you put this in someone, they’re never going to want it taken out.”

Crothall said that her company hadn’t looked at how weight loss is maintained once the device is removed but was marketing the device for long-term use. She said that trial participants were offered counseling to help them modify their eating habits, but there was only anecdotal evidence that any of them made changes.

Cederhag said he’d eventually like to get to the point where he no longer needed the pump, but if he couldn’t maintain his lower weight without it, he’d be fine with keeping the AspireAssist in indefinitely.

“If I have to continue to flush my stomach every day or every other day, then so be it,” he said.

Backups and Bulimia

Ayoob also brought up the point that chunks of food could get stuck in the tubing of the device, much in the way debris backs up in a sink drain. One trial participant reported such “clogging,” and had to avoid cauliflower, broccoli, Chinese food, stir-fry, snow peas, pretzels, chips and steak.

“With the tube it’s much easier to eat smooth and creamy foods like ice cream, pudding and cake versus hard or crunchy foods like fruits, vegetables and lean meats” — the foods most apt to promote weight loss — Ayoob said

Cederhag said that clogged tubing was a problem for him at the beginning. But after experience and training himself to chew food more thoroughly it disappeared after the first few weeks of use.

Ayoob also worried that the pump was perhaps too much like a “bulimia machine” that mimicked the purging behavior seen in those with eating disorders. Crothall said patients were screened for bulimia beforehand. To prevent abuse, the pump only performs a predetermined number of aspirations until the system must be reset by a doctor.

Cederhag said the device helped him avoid “disordered eating” by allowing him to enjoy normal meals while still losing weight.

“I don’t want to be seated at the table with an empty plate. This way I can eat together with my friends and my family, I can drink my beer or wine if I want to. And then I can just let go of 30 percent.”